(1) Field of the Invention
The present invention relates to a video and audio reproduction apparatus and a method thereof and, in particular, to a video and audio reproduction apparatus and a method thereof which allow reproduction of a video and audio stream.
(2) Description of the Related Art
In recent years, many video recording and reproduction apparatuses which reproduce a compression-coded video and audio stream have been marketed and become widely used.
A video and audio stream is compression-coded for every group to be processed, for example, every packet. The compression-coded video and audio stream is decoded, for every group to be processed, and reproduced.
For instance, in the case where an audio stream is compression-coded, 1024 audio samples are collectively compression-coded as a single group to be processed. The compression-coded audio stream is decoded, for every group to be processed, and reproduced.
A scheme used for compression-coding includes, for example, audio compression-coding schemes such as MPEG-1 Audio Layer-3 (MP3), Advanced Audio Coding (AAC), and Windows® Media Audio (WMA), and video compression-coding schemes such as Moving Picture Experts Group phase 2 (MPEG-2) and H. 264 (H. 264/MPEG-4 AVC, MPEG-4 Part 10 Advanced Video Coding).
Conventionally, one group to be processed has contained only one block to be processed in a coded video and audio stream. For this reason, a decoding unit that processes a video and audio stream having groups to be processed each containing only one block to be processed has been included in a conventional video recording and reproduction apparatus.
However, a video and audio stream having groups to be processed each containing plural blocks to be processed has recently been increasing. For example, there is an audio stream having groups to be processed each containing plural blocks to be processed of audio data that is the same audio data but has a different bit rate, e.g. payloads (for instance, refer to Non-Patent Reference 1: Advanced Systems Format (ASF) Specification Revision 01. 20. 02 Microsoft Corporation June 2004.).
In an audio stream having groups to be processed each containing plural blocks to be processed, it is possible to hold audio data with the same contents constituted by plural bit rates. As a result, when reproducing audio data, it is possible to select audio data with any bit rate from among plural pieces of audio data with the same contents constituted by the bit rates and to reproduce the selected audio data. The audio stream can also hold audio data that differs for every block to be processed.